The burden of independence: inorganic carbon utilization strategies of the sulphur chemoautotrophic hydrothermal vent isolate Thiomicrospira crunogena and the symbionts of hydrothermal vent and cold seep vestimentiferans
Scott, K.M.; Bright, M.; Fisher, C.R. (1998). The burden of independence: inorganic carbon utilization strategies of the sulphur chemoautotrophic hydrothermal vent isolate Thiomicrospira crunogena and the symbionts of hydrothermal vent and cold seep vestimentiferans. Cah. Biol. Mar. 39(3-4): 379-381. https://dx.doi.org/10.21411/CBM.A.4CA683A6
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more
Also appears in:(1998). Proceedings of the First International Symposium on Deep-Sea Hydrothermal Vent Biology: Funchal, Madeira, Portugal 20-24 October 1997. Cahiers de Biologie Marine, 39(3-4). Station Biologique de Roscoff: Roscoff. 219-392 pp., more
|   |
| Authors | | Top |
- Scott, K.M.
- Bright, M.
- Fisher, C.R.
|
|
|
| Abstract |
The actual availability in situ of inorganic carbon to vestimentiferan symbionts, as well as to free-living T. crunogena, is difficult to assess. Macroscopically, inorganic carbon is abundant. Diffuse flow hydrothermal fluid and vestimentiferan blood are enriched with inorganic carbon compared to the 2 mM found in seawater. Microscopically, however, the concentration of inorganic carbon may be much lower. The pool of inorganic carbon available to both T. crunoge a and vestimentiferan symbionts may be diffusion limited. Vestimentiferan symbionts are packed in the trophosome. Given their high rates of carbon fixation, it is conceivable that inorganic carbon availability at the symbiont cell surface may be depleted relative to the blood and coelomic fluid. Free-living chemoautotrophs may also face localized depletions in the pool of inorganic carbon at the cell surface, especially when growing in thick mats, which may constrain diffusion of inorganic carbon to the cells in the interior of the mat. T. crunogena is capable of growing in the presence of extremely low concentrations of inorganic carbon (<20 mu M). Such an ability would allow these cells to survive in low inorganic carbon microhabitats. Half-saturation constants, as well as the form(s) of extracellular inorganic carbon used by vestimentiferan symbionts and T. crunogena, were determined to compare inorganic carbon use by a free-living sulphur chemoautotroph to symbionts inhabiting hosts with extensive morphological and enzymatic adaptations for efficient delivery of inorganic carbon to them. |
|
